Ok, strap yourself in, it’s gonna be a bumpy ride.
Posing/Staging: If you’re doing a still then this is ultra critical.
Try rotating the camera a little so we can see both the legs, one of the legs is hidden and a little confusing. Also the hands are a bit “edge-on” to the camera. Hands are a very expressive bit of the body, so try get them in such a way that we can really see what shape/pose they are in.
The big danger in 3d is that as we work with a 3d model for hours, we build up a mental image of the thing. You’ve probably rotated and panned around that thing a million times, so you know what it looks like even with your eyes closed. As a viewer i don’t have that benefit, i can only see what you’re showing me. Try looking at the image alpha and ask yourself if you can clearly see what kind of pose the character is in.
Depth of Field: is a great way of adding a bit of photographic realism, but at this preliminary lighting stage I’d stay away from it. Get the image looking good without DOF then bring it in as a final stage. Also keep in mind that too much DOF usually makes things look really small, like an insect in a nature documentary.
Lights: Key, Fill, Back. If you’re going for a contrasty look then you might want to skip a fill light, but a back light would really lift your images, pick out the edges of the unlit areas.
oh and lastly: Don’t stop! Keep at it man!